alien invasive species

例句：

1. 1. The alien species has been causing problems in the ecosystem.
   这种外来物种已经在生态系统中造成了问题。
2. 2. The alien species is not native to this region.
   这种外来物种不是这个地区的原生种。
3. 3. Aliens are often seen as a threat to society.
   外星人通常被视为对社会的威胁。